What is the recommended Continuous Positive Airway Pressure (CPAP) airflow setting for a patient with obstructive sleep apnea?

CPAP Starting and Maximum Pressure Settings

For obstructive sleep apnea, start CPAP at 4 cm H₂O and titrate upward in 1 cm H₂O increments every 5 minutes until apneas, hypopneas, RERAs, and snoring are eliminated, with a typical maximum of 15 cm H₂O before considering switching to BiPAP. 1

Initial CPAP Settings

• Start at 4 cm H₂O for both pediatric and adult patients 1
• This minimum starting pressure applies universally regardless of OSA severity 1

Titration Protocol

Pressure Increases:

• Increase CPAP by at least 1 cm H₂O increments 1
• Wait a minimum of 5 minutes between each adjustment 1
• Continue increasing until all obstructive events are eliminated: apneas, hypopneas, respiratory effort-related arousals (RERAs), and snoring 1

Pressure Exploration:

• Once control is achieved, you may explore upward by an additional 2-5 cm H₂O to address residual upper airway resistance that can cause arousals and insomnia 1
• Do not exceed 5 cm H₂O above the pressure that eliminated respiratory events 1

Maximum CPAP Pressure and BiPAP Transition

Critical threshold at 15 cm H₂O:

• If obstructive events persist at 15 cm H₂O of CPAP, switch to BiPAP 1, 2
• Patient intolerance to high CPAP pressures is also an indication to trial BiPAP 1

BiPAP starting settings if needed:

• Minimum starting IPAP: 8 cm H₂O 1, 2
• Minimum starting EPAP: 4 cm H₂O 1, 2
• Maintain IPAP-EPAP differential of 4-10 cm H₂O 2
• Maximum IPAP for adults ≥12 years: 30 cm H₂O 2
• Maximum IPAP for children <12 years: 20 cm H₂O 2

Important Clinical Caveats

Patient tolerance supersedes protocol:

• If the patient awakens complaining pressure is too high, immediately reduce to a comfortable level that allows return to sleep 1, 2
• Resume titration from this lower pressure 1

Split-night studies:

• Use identical titration algorithms as full-night studies 1
• Consider larger increments (2-2.5 cm H₂O) given shorter titration duration 1
• Be aware that split-night studies may yield lower pressures for mild-to-moderate OSA patients who don't manifest maximal severity early in the night 1

Higher starting pressures:

• May be selected for patients with elevated BMI 2
• May be appropriate for retitration studies 1

Common Pitfalls to Avoid

• Do not confuse these chronic OSA titration guidelines with acute cardiogenic pulmonary edema management, which uses different pressure settings 3
• Do not increase pressure beyond what eliminates respiratory events unless exploring for residual resistance (and then only by 2-5 cm H₂O maximum) 1
• CPAP remains the gold standard first-line treatment with 60-70% adherence rates 4
• Alternative treatments like oral appliances are less effective at reducing respiratory disturbances but may be preferred by some patients for convenience 5